mysql already has its socket path hardcoded to to
/run/mysqld/mysqld.sock.
There's not much value in making the pidDir configurable, which also
points to /run/mysqld by default.
We only seem to use `services.mysql.pidDir` in the wordpress startup
script, to wait for mysql to boot up, but we can also simply wait on the
(hardcoded) socket location too.
A much nicer way to accomplish that would be to properly describe a
dependency on mysqld.service. This however is not easily doable, due to
how the apache-httpd module was designed.
As we don't need to setup data directories from ExecStartPre= scripts
anymore, which required root, but use systemd.tmpfiles.rules instead,
everything can be run as just the mysql user.
define commands like "waiting for the mysql socket to appear" or "setup
initial databases" in a let expression, so the main control flow becomes
more readable.
We need to keep using `RuntimeDirectory=mysqld`, which translates to
`/run/mysqld`, as this is used for the location of the file socket, that
could differ with what is configured via `cfg.pidDir`.
Before, changing any peers caused the entire WireGuard interface to
be torn down and rebuilt. By configuring each peer in a separate
service we're able to only restart the affected peers.
Adding each peer individually also means individual peer
configurations can fail, but the overall interface and all other peers
will still be added.
A WireGuard peer's internal identifier is its public key. This means
it is the only reliable identifier to use for the systemd service.
5404595b55 relocated code but kept
one backslah too many, leading to
$ tmux
error creating /run/user/$(id -u)/tmux-1000 (No such file or directory)
/run/user/$UID/ is created by pam_systemd(3) which also populates
XD_RUNTIME_DIR with that value.
Alternatively, TMUX_TMPDIR might simply default to XDG_RUNTIME_DIR
without providing the same directory yet again as default string in
parameter substitution, however such behaviour change is subject to
another patch.
In fact, with `security.polkit.enable = false` systemd_logind(8) fails
to start and /run/user/$UID/ is never created for unprivileged users
in proper login sessions; XDG_RUNTIME_DIR would consequently not be
set either.
Removing the fallback to /run/user/$UID/ would have caused TMUX_TMPDIR
to be empty, which in turn would lead tmux(1) to use /tmp/. This
effectively breaks the idea of isolated sockets entirely while hiding
errors from the user.